Issue link: https://read.uberflip.com/i/1146286
eBay | 119 Most of these 36 images are downloaded in the middle of the graph, where you can see a clear stairstep pattern of just two requests at a time. If these were split across http://pics1.ebaystatic.com and http://pics2.ebaystatic.com, for example, four images could be downloaded in parallel, thus speeding up the overall page load time. There is a trade-off in performance between splitting images across multiple hostnames and reducing DNS lookups (Rule 9), but in this case, downloading 36 images, 4 at a time, is worth an extra DNS lookup. A nice performance trait is that three of the scripts are downloaded at the bottom of the page. These scripts are related to the user's eBay "Favorites" and are probably not required for rendering the page. eBay has followed the recommended practice here of loading scripts at the bottom, which Chapter 6 explained as valuable because it doesn't block downloading and rendering.